LAS VEGAS – Seven grandmasters and one international master tied for first place in the 23rd annual North American Open, which drew 670 players here to Bally’s Las Vegas Hotel and Casino.

The winner on tiebreaks was GM Giorgi Kacheishvili, who admitted he missed a “beginner’s problem” that could have enabled him to win clear first place in his final round game against GM Timur Gareev, who also tied for first.

“I just didn’t see it,” Kacheisvili said of move in which Gareev blundered his rook by playing Kh2 and Kacheisvili responded with Kh4 instead of Qh8.

“I was very tired,” he said.

Kachheisvili, who runs the Grandmaster School at the Marshall Chess Club in New York City, also credited Bf6 and Ne7 as critical moves in his game against Gareev.